Speed control device

ABSTRACT

A speed control device having a first gear member and a second gear member and including an operable means to connect the first gear member and the second gear member together for rotation in the same direction in a manner that the speed of the slowest gear member will determine the speed of the other gear member.

atent n 1 United States Coeppert Mar. 27, 1973 SPEED CONTROL DEVBCE 21Appl. No.: 140,362

[52] U.S. Cl. ..'74/675 [51] Int. Cl .JFlGh 37/08 [58] Field of Search..74/675, 803

[56] References Cited UNITED STATES PATENTS 7 3,295,395 1/1967 Willard..74/675 2,422,343 6/1947 Duer .......74/675 5/1956 Andrus ..74/675l/l961 Fraga ..74/675 Primary Examiner-C. J. Husar Attorney-Thomas A.Hauke TRACT A speed control device having a first gear member and 4 5Drawing figures PATENTEUMARZYIQB SHEET 10F 2 INVENTOR. Z PW/A/ 605 5/37BY I ///o/way SPEED CONTROL DEVICE BACKGROUND OF THE INVENTION Prior tothis invention, reverted epicyclic transmission having an input powermeans and a speed control input means have had the problem of speedcontrol. This is due to the fact that when the torque on the outputshaft created by the load is greater than the torque applied to theinput means of the transmission, it will cause the undesirable result ofhaving the speed control input means turn at the speed dictated by thespeed of the output means.

SUMMARY OF THE INVENTION The invention disclosed herein overcomes thisand other problems associated with the prior art reverted epicyclictransmissions in that the speed of the output shaft is determined solelyby the input side of the transmission.

According to the present invention, the speed control device includes ashaft which rotatably supports a first gear and a second gear. A pair ofcam members are interposed between the first and second gears whereby alocking of the first and second gears together may be effected in amanner that for the gears to turn they must both turn in the Samedirection and at the speed of the slowest rotating gear.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation of areverted epicyclic gear train incorporating the features of the presentinvention;

FIG. 2 is a view illustrating one extreme position of the locking pinand the inner races of the bearing assemblies;

FIG. 3 is a view illustrating the other extreme position of the lockingpin and the inner races of the bearing assemblies;

FIG. 4 is an exploded perspective view of the invention; and

FIG. 5 is a view illustrating the axial path of the locking pin.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, thereis shown therein a variable speed reverted epicyclic transmission 10,operably disposed within a housing 11. A power input shaft 12 isjoumalled within the housing 11 in bearings 15, 16 and 17. The powerinput shaft 12 has a portion 18 which is of reduced diameter having itsaxis offset from the axis of the power input shaft 12 so that thereduced portion 18 acts as an eccentric drive shaft upon rotation of thepower input shaft 12. The reduced shaft portion 18 supports bearings 20and 21, the outer races of which receive gears 24 and 25, respectively.Gear 24 is adapted to intermesh with an internal gear portion 27 of adriving gear 28. The driving gear 28 is rotatably carried by the bearing16 which is disposed on the power input shaft 12. Gear 28 is formed withan external gear portion 30 which is intermesh with a control input gear31. Gear 31 is fixedly secured to a speed control input shaft 34 whichis rotatably joumalled through the housing 11 and is connected outsidethe housing to a variable speed control motor (not shown) in awell-known manner.

Gear 25 is adapted to intermesh with an internal gear portion 35 of adriving gear 36. The driving gear 36 is rotatably carried by the bearing17 which is disposed on the power input shaft 12. Gear 36 is formed withan external gear portion 39 which is intermesh with an output gear 40.Output gear 40 is fixedly secured to an output shaft 41 which isrotatably joumalled through the housing 11 and is connected outside thehousing 1 1 to the load.

As shown in FIG. 1 a cam member having an axial bore 51 is secured bypins 52 (only one is shown).

to the gear 24. A counterbore 55 is formed, within cam member 50, on anaxis which intersects the axis of the axial bore 51. Supported withincounterbore 55 is a bearing assembly 56 comprised of an outer racemember 58 and an inner race member 59. Bearing assembly 56 rotatablysupports the cam member 50 as it rotates in unison with the gear 24. Asecond cam member 60 having an axial bore 61 is secured by pins 62 (onlyone shown) to the gear 25. A counterbore 65 is formed, within cam member60, on an axis which intersects the axis of the axial bore 61. Supportedwithin the counterbore 65 is a bearing assembly 66 comprised on an outerrace member 68 and an inner race member 69. Bearing assembly 66rotatably supports cam member 60 as it rotates in unison with the gear25 The inner race member 59 of cam member 50 and theinner race member 69of cam member 60 are prevented from rotating relative to the reducedshaft portion 18 by means 'of a pin 72 which is pivotly secured toreduced shaft portion 18. The pin '72, as shown in FIGS. 1 and 4, isdisposed to engage a semi-circular recess 74 formed within inner racemember 59 and a semi-circular recess 75 formed within inner race member69.

, The connection of pin 72 to reduced shaft portion 18 is illustrated inFIG. 4. A bore 78 is formed within reduced shaft portion 18 and isadapted to receive a bushing 79. A bore is formed within bushing 79 andis adapted to snugly receive the pin 72. An elongated slot 81 is formedin reduced shaft portion 18, having its major axis at right angles tothe axis of bore 78. As shown in FIG. 5, the pin 72 is inserted throughthe slot 81 and the bore 80 of bushing '79. The pin 72 is free to movein the elongated shot 81 in a pivotable motion as illustrated in FIG. 5by the dotted and solid lines showing the extreme pivotable position ofpin 72.

As the gears 24 and 25 rotate about reduced shaft portion 18, theirrespective cam members 50 and 60 will rotate therewith. The cam members50 and 60 in rotating will effect their respective inner races 59 and 69to move laterally about bushing 79. Although the inner races 59 and 69will move laterally about bushing 75, they are held from rotating aboutreduced shaft portion 18 by the pin 72. Due to the eccentric path oftravel of the cam member 50 and 60 as they rotate about the reducedshaft portion 18, the inner races 59 and 69 are moved laterally in awobble like motion. FIGS. 2 and 3 show the extreme positions that theinner races 59 and 69 will take as the bearing assembly 66 rotates aboutreduced shaft portion 18. 7

Assume that at the initial movement of gears 24 and 25 the gears andtheir associated cam members 50 and 60 are in the position as depictedin FIG. 2. As the cam members 50 and 60 rotate the inner races 59 and 69will move laterally in a leftward direction to the position asillustrated in FIG. 3. As the cam members rotate another 180 the innerraces 59 and 69 will again move to the position as depicted in FIG. 2.

In order to clearly understand the principles of the invention, theinteraction of the various members of the speed control device will bedescribed under a given condition. Let us assume that the external loadforces on the output shaft 41 are such that they will try to effect theclockwise rotation of output gear 41, as viewed from the left in FIG. 1,at a higher rotational speed than that of the speed control input gear31. Gear through gear 36 will inturn, try to rotate clockwise as viewedfrom the left in FIG. 3, at a higher speed than that at which the gear24 through gear 28 is being driven. This will be prevented fromhappening by the interaction of cam members 50 and 60. As gear 25attempts to effect the rotation of gear 24 at a speed greater than whichit is being driven by the input speed control gear 31, a rotationalforce is applied to'cam member 60. This force will try to rotate cammember 60 in a clockwise movement, as viewed from the left in FIG. 1, ata higher speed than cam member 50. Cam member. 60 being afixed to rotatewith gear 25 will rotate about the axis of the reduced shaft portion 18.However, the inner race 69 being disposed within counterbore 65 of cam60-at an angle which innersects the axis of the reduced shaft portion 18is prevented from rotating about the axis of the reduced shaft portion18 by pin 72. Therefore, the rotational effect of cam member 60 will beimparted to its inner race 69 to effect a lateral displacement of theinner race 69. As the inner race 69 is displaced laterally towards theinner race 59 the two adjacent faces of inner race 69 and inner race 59will move into wedging engagement and the laterallydisplacing forcewhich has been imparted to inner race 69 will be imparted to inner race59.

Since inner race 59 is also prevented from rotating about the axis ofreduced shaft portion 18 by operation of the pin 72, it will also bedisplaced laterally in the same direction that inner race 69 is beingdisplaced.

- Since gear 24 and its cam member 50 is being positively drive by avariable speed control motor (not shown) through gears 31 and 28, theforce of the inner race 59 against its respective cam member 50 will actas a brake and will result in a developing force in the oppositedirection which opposed the force in the leftward direction as viewed inFIG. 1. Thus a braking action on the gear 25 is experience whichmaintains the output gear 40, through gear 36 at the desired rotationalspeed. 1

Although the illustrative embodiment of the invention has been describedin considerable detail for the purpose of disclosing a practicaloperative structure whereby the invention may be practicedadvantageously, it is to be understood that the particular apparatusdescribed is intended to beillustrative only and that the novelcharacteristics of the invention may a shaft; a first gear rotatablymounted on said shaft;

a second gear rotatably mounted on said shaft;

a first cam member having an axial bore secured to said first gear;

a second cam member having an axial bore secured to said second gear;

a first bearing assembly disposed in said axial bore of said first car-nmember;

second bearing assembly disposed in said axial bore of said second earnmember; and locking means secured to said shaft operable to connect saidfirst gear and second gear together for rotation in the same directionand at a rate determined by the rotation of the slowest gear.

2. A speed control device according to claim 1 wherein each of saidfirst and second bearing assemblies comprises:

an outer race engaged with said axial bore of same cam members; and.

an inner race rotatably mounted in said outer race wherein said lockingmeans is secured to said inner races to prevent the inner races fromrotating around said shaft effecting said first and second bearingassemblies to wobble upon the rotation of said first and second gears.

33. A power transmitting device according to claim 2 wherein saidlocking means includes:

a first bore in said shaft;

a first pivot pin rotatably secured in said first bore;

a second bore in said shaft located 90 from said first bore; and v asecond pivot pin secured in said second bore and connected to said firstpivot pin and said inner races of said first and second bearingassemblies.

4. A variable speed transmission unit comprising:

a first input drive means;

a second input speed control drive means;

an output drive means adopted to receive the input from said first andsecond drive means;

a first gear connected to said second input means;

a second gear connected to said output drive means;

a first cam member secured to said first gear;

a second cam member secured to said second gear, and means operable toeffect the engagement of said first and second cam members effecting theconnection of said first and second gears for rotation in the samedirection and at a rate determined by the rotation of the slowest gear.

1. A speed control device comprising: a shaft; a first gear rotatablymounted on said shaft; a second gear rotatably mounted on said shaft; afirst cam member having an axial bore secured to said first gear; asecond cam member having an axial bore secured to said second gear; afirst bearing assembly disposed in said axial bore of said first cammember; a second bearing assembly disposed in said axial bore of saidsecond cam member; and locking means secured to said shaft operable toconnect said first gear and second gear together for rotation in thesame direction and at a rate determined by the rotation of the slowestgear.
 2. A speed control device according to claim 1 wherein each ofsaid first and second bearing assemblies comprises: an outer raceengaged with said axial bore of same cam members; and an inner racerotatably mounted in said outer race wherein said locking means issecured to said inner races to prevent the inner races from rotatingaround said shaft effecting said first and second bearing assemblies towobble upon the rotation of said first and second gears.
 3. A powertransmitting device according to claim 2 wherein said locking meansincludes: a first bore in said shaft; a first pivot pin rotatablysecured in said first bore; a second bore in said shaft located 90* fromsaid first bore; and a second pivot pin secured in said second bore andconnected to said first pivot pin and said inner races of said first andsecond bearing assemblies.
 4. A variable speed transmission unitcomprising: a first input drive meanS; a second input speed controldrive means; an output drive means adopted to receive the input fromsaid first and second drive means; a first gear connected to said secondinput means; a second gear connected to said output drive means; a firstcam member secured to said first gear; a second cam member secured tosaid second gear, and means operable to effect the engagement of saidfirst and second cam members effecting the connection of said first andsecond gears for rotation in the same direction and at a rate determinedby the rotation of the slowest gear.